The inventors have observed that chemical vapor deposition (CVD) of cobalt can be used as a metal deposition technique for applications such as forming metal interconnects in an integrated circuit. Cobalt may be deposited by chemical vapor deposition within an opening, such as a via or trench, in thin layers and then treated to drive out impurities such as carbon, hydrogen, and oxygen.
Thus, the inventors have provided improved methods and apparatus for depositing a cobalt layer in features formed on a substrate.